1. Field of the Invention
The present invention relates to digital image photography and more particularly to a method for photographing a panoramic image.
2. Description of the Related Art
Generally, a photographing unit of a digital-image photographing apparatus can obtain a picture formed within a focal length of its lens. The obtained picture has a viewing angle range of about 30˜50 degree in the case of a general camera, which is narrower than the viewing angle of a human being (about 150˜200 degree). Methods for creating an image with an angle of view similar to or more than the viewing angle of a human require, photographing multiple pictures with an appropriately changed photographing angle, and then putting together the photographed pictures in consecutive order to create one image. Such a method is referred to as panoramic photography.
In a panoramic image photographing mode, a digital-image photographing apparatus photographs multiple pictures in consecutive order in a horizontal or vertical direction, and stores the pictures in a memory. Later, the pictures stored in the memory are provided to an image processor, and are put together into one image. The image processor may be internal or external to the photographing apparatus.
In order to eliminate the difference in color and image boundaries between the pictures, multiple pictures are photographed in such a manner that the boundaries are appropriately overlapped, and the pictures are aligned in such a manner that the overlapped portions are synchronized with each other. Then, after the image processing operations, such as stitching and blending, the multiple pictures are smoothly put together into one image.
In photographing such a panoramic image, it is important to photograph respective pictures in such a manner that the pictures are aligned as accurately as possible. Therefore, a user may manually photograph an image using an auxiliary device such as a tripod. In addition, recently, there is provided a method for rotating a photographing apparatus in accordance with each picture to be photographed in panoramic photography, by using auxiliary devices. The devices are attached to a tripod, etc. and a corresponding photographing apparatus is mounted thereon. An example of such a technology is Korea Patent Application No. 2003-0052444, entitled “Camera and Method for Photographing Panorama Picture” (Application date: Jul. 29, 2003, Applicant: Samsung-Techwin, and Inventor: Bae Sung-chul). Another method a photographing apparatus is provided with a device for detecting a rotation angle, and a user-preset rotation angle of the photographing apparatus. Accordingly, in panoramic photography, when a portable terminal is rotationally moved according to the user-set rotation angle, each picture is photographed.
There is further provided a method for more accurately aligning respective pictures in panoramic photography, without an auxiliary device or additional hardware combined with a corresponding photographing apparatus. In this method, a part of the boundary of a previously photographed image is displayed while appropriately overlapping an image to be currently photographed so that a user can adjust an appropriate photography position by synchronizing the previously photographed image and the currently photographed image with each other. An example of such a technology is United States Patent Publication No. 2004-0189849, entitled “Panoramic Sequence Guide” (Application date: Mar. 31, 2003, and Inventor: Gregory V. Hofer).
Such panoramic photography requires a user to be more sophisticated and skillful in the operation than for photography of a single-photo, and thus a more convenient operation mechanism and a more efficient photography mechanism are needed.